En masse is defined as something is done collectively, or that it is done all at the same time or all together.(adverb)
An example of en masse is when a concert ends and the entire audience all tries to exit the stadium at the same time.
See en masse in Webster's New World College Dictionary
Origin: Fr, lit., in mass
See en masse in American Heritage Dictionary 4
Origin: : en, in
Origin: + masse, mass.
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